Background: Stressful life events impact mental health and may lead to psychotropic medication use, an objective outcome determinable in large-scale registries. More research is needed on the association between stressful life events and psychotropic medication use, and on identifying risk groups. Methods: Doetinchem Cohort Study data (n=6141, age 56.8±10.4 years) was linked to nationwide Dutch registry data on life events and psychotropic medication use. Potential modifying factors were based on DCS data. Discrete-time survival analyses were performed. Results: Loss of a partner was associated with increased psychotropic medication use (OR [95% CI], 1.93 [1.54-2.40]). For loss of a child, increased psychotropic medication use was only observed in men (OR, 2.68 [1.37-5.26], women 1.08 [0.55-2.11]). Active coping also modified this association, with an increased medication use among individuals with higher pre-baseline active coping (continuous score, OR, 1.87 [1.14-3.07]). For separation, increased risk of medication use was only observed among men (OR, 1.75 [1.12-2.73], women: 1.01 [0.64-1.61]), and among those with pre-baseline high alcohol use (OR 2.41 [1.30-4.47], non-high alcohol use, 1.11 [0.76-1.62]). The association of loss of a partner was not modified by any of the investigated factors. Conclusions: Losing a partner was associated with an increased risk of psychotropic medication use. Additionally, men but not women had an increased risk of medication use following the loss of a child or partner separation. Alcohol use and an active coping style also modified some of these associations and may indicate groups with increased vulnerability to separation or loss of a child.

INTRODUCTIONChildhood vaccination coverage has declined in recent years in many countries, including the Netherlands.AIMTo understand differences in coverage between population subgroups in the Netherlands over time, we studied sociodemographic factors associated with measles-mumps-rubella (MMR) and diphtheria-tetanus-pertussis-poliomyelitis (DTaP-IPV) vaccination.METHODSWe conducted a national retrospective database study including children born between 2008 and 2020. Individual-level data linkage allowed examination of associations of sociodemographic variables with MMR and DTaP-IPV vaccination status at age 2 years. We calculated coverage for each variable, stratified by birth cohort. Multivariable Poisson regression assessed independent associations and changes in coverage over time.RESULTSMMR coverage decreased in all population subgroups (overall 95% in cohort 2008 and 89% in cohort 2020), more substantially in some. In multivariable analysis, children of non-Dutch origin, particularly Moroccan and Turkish origin, showed more pronounced declines (respectively -25% and -12% as children of Dutch origin in cohort 2020). Among children not attending daycare and children living in larger families (≥ 4 children), coverage declined faster than in those attending daycare and living in smaller families (both -12% in cohort 2020). Coverage among children of self-employed mothers and children in the lowest income households was lower than among children of mothers in employment and the highest income households (respectively -8% and -7% in cohort 2020). Trends for DTaP-IPV vaccination were nearly identical.CONCLUSIONChildhood vaccination coverage in the Netherlands declined substantially, with increasing disparities between sociodemographic groups. Vaccination efforts should be prioritised to protect public health equitably.

This observational experimental study was aimed at measuring SARS‐CoV‐2 dispersion via air and deposition onto surfaces in indoor spaces at short range (0.8 m) and long range (4.0 m) during the speaking and singing of mildly symptomatic COVID‐19 patients. Ten patients were invited to sing and speak in unventilated rooms. Air and surface samples were taken and analyzed for SARS‐CoV‐2 by qPCR and cell culture assay. Seventy‐three of 120 air samples and 2 of 80 surface samples tested positive by qPCR. Concentrations were too low to be quantified. Culturing to confirm infectivity was unsuccessful for all samples. High nasal virus concentration in patients, a high number of symptoms, and short symptom duration correlated with a higher probability of PCR‐positive air samples. Impingers were significantly more effective air samplers than impactors. No significant effect was found for patient age, oropharyngeal virus concentration, the presence of systemic symptoms, vaccination status, the number of coughs during measurements, room temperature, humidity, time, proximity, respiratory activity, or voice amplitude during experiments. Two supporting experiments were performed on aerosol dispersion and sampler equipment tests. They confirmed that aerosols spread throughout the room homogeneously and that selected sampler equipment can detect genetic material from environmental samples. This study adds to the body of evidence regarding the dispersion of SARS‐CoV‐2 RNA in range of a few meters indoors.

Background:Post-COVID-19 condition (PCC) risk may have changed due to vaccination status, virus variants, prior infections, and other factors. We aimed to estimate PCC prevalence for one year in individuals infected with SARS-CoV-2 during autumn 2023, controlling for pre-infection symptoms and prevalence in recently uninfected participants. Methods:VASCO, a Dutch ongoing prospective cohort, collects three-monthly questionnaires and six-monthly SARS-CoV-2 serology. Participants indicated severity of 23 symptoms on a five-point Likert scale, and of fatigue and concentration problems on the Checklist Individual Strength. We matched participants who did with those who did not report a SARS-CoV-2 infection between September 25, 2023 and January 7, 2024, and censored follow-up time for both upon serological or antigen test evidence of infection. We estimated PCC-prevalence as the excess prevalence of at least one PCC-related symptom between matched infected and uninfected participants at 90, 180, 270, and 360 days post-infection. Additionally, participants could self-attribute long-term symptoms to SARS-CoV-2. Findings:We 1:1 matched 5621 infected to 5621 uninfected participants. The PCC prevalence, estimated as the marginal mean excess prevalence of PCC-related symptoms between infected and uninfected participants, was 0.2% (95% confidence interval: -1.9 to 2.3, p = 0.84) at 90 days, 0.5% (-1.6 to 2.6, p = 0.63) at 180 days, 0.7% (-1.3 to 2.8, p = 0.48) at 270 days, and 0.0% (-2.1 to 2.1, p = 0.99) at 360 days. Excess prevalence of new mild and severe long-term symptoms self-attributed to SARS-CoV-2 between infected and uninfected participants were both elevated at 90 days (mild: 7.2% (5.1-9.2), severe: 0.6% (0.4-0.8)) and 180 days (mild: 3.2% (2.0-4.4), severe: 0.3% (0.2-0.4)) post-infection (all p-values <0.0001), but no longer thereafter. Interpretation:This double-controlled study, incorporating pre- versus post-infection and uninfected symptom data, found a low risk of PCC among a community-dwelling adult population infected during the autumn 2023 SARS-CoV-2 wave. The prevalence of PCC-related symptoms in infected and uninfected individuals was not significantly different at 90-360 days post-infection. The excess prevalences of self-attributed long-term symptoms were elevated at 90 and 180 days post-infection but no longer from 270 days onwards. These findings suggest that the 2023 wave inferred a lower PCC risk than during the pandemic period. Funding:Funded by the Dutch Ministry of Health, Welfare and Sport.

OBJECTIVES:Evaluation of the presence and effect of SARS-CoV-2 co-infections on disease severity. METHODS:We collected both symptom data and nose- and throat samples from symptomatic people during the 2022/2023 respiratory season in a large participatory surveillance study in the Netherlands, and tested these for 18 respiratory viruses, including SARS-CoV-2. We compared reported health status, symptoms and odds of having a single respiratory viral infection or co-infection with SARS-CoV-2 and another respiratory virus. RESULTS:In total, 4655 samples were included with 22% (n=1017) testing SARS-CoV-2 positive. Of these 11% (n=116) also tested positive for a second respiratory virus. The most frequently occurring co-infections in SARS-CoV-2 positive participants were with rhinovirus (59%; n=69), seasonal coronaviruses (15%; n=17), and adenovirus (7%; n=8). Participants with a co-infection with one of these three viruses did not report more severe disease compared to those with a SARS-CoV-2 mono-infection. The odds of experiencing SARS-CoV-2 co-infection with seasonal coronavirus or rhinovirus were lower compared to the odds of the respective non-SARS-CoV-2 mono-infection (OR: 0.16, CI 95%: 0.10 - 0.24; OR: 0.21 CI 95%: 0.17 - 0.26; respectively). CONCLUSIONS:SARS-CoV-2 co-infections with rhinovirus, seasonal coronavirus, and adenovirus are frequently observed in the general population, but are not associated with more severe disease compared to SARS-CoV-2 mono-infections. Furthermore, we found indications for inter-virus interaction with rhinovirus and seasonal coronavirus, possibly decreasing the risk of co-infection.

Fatigue is one of the most common persistent symptoms of SARS-CoV-2 infection. We aimed to assess fatigue during and after a SARS-CoV-2 infection by age, sex, presence of a medical risk condition, SARS-CoV-2 variant and vaccination status, accounting for pre-infection fatigue and compared with uninfected individuals. We used data from an ongoing prospective cohort study in the Netherlands (VASCO). We included 22,705 first infections reported between 12 July 2021 and 9 March 2024. Mean fatigue scores increased during infection, declined rapidly in the first 90 days post-infection, but remained elevated until at least 270 days for Delta and 120 days for Omicron infections. Prevalence of severe fatigue was 18.5% before first infection. It increased to 24.4% and 22.5% during acute infection and decreased to 21.2% and 18.9% at 90 days after Delta and Omicron infection, respectively. The prevalence among uninfected participants was lower than among matched Delta-infected participants during the acute phase of the infection and 90 days post-infection. For matched Omicron-infected individuals this was only observed during the acute phase. We observed no differences in mean post- vs pre-infection fatigue scores at 90-270 days post-infection by vaccination status. The impact of SARS-CoV-2 infection on the prevalence of severe fatigue was modest at population level, especially for Omicron.

Introduction: To understand differences in vaccination coverage between population subgroups in the Netherlands over time, we studied sociodemographic factors associated with measles-mumps-rubella (MMR) and diphtheria-tetanus-pertussis-poliomyelitis (DTaP-IPV) vaccination. Methods: We conducted a national retrospective database study including children born in 2008-2020. Individual-level data-linkage allowed examination of associations of sociodemographic variables with MMR and DTaP-IPV vaccination status at 2 years of age. Coverage for each variable, stratified by birth cohort, was calculated. Multivariable Poisson regression assessed independent associations and changes in coverage over time. Results: MMR coverage decreased in all population subgroups (overall 95% to 89% in 2008 and 2020 cohorts), with more substantial declines in some groups. The multivariable analysis showed that Dutch children of non-Dutch origin, particularly those of Moroccan and Turkish origin showed more pronounced declines (-25% and -12% compared to children of Dutch origin in cohort 2020, respectively). Among children not attending day care and children living in larger families (≥4 children), a faster decline in coverage was observed compared to those attending day care and living in smaller families (both -12% in cohort 2020). Among children of self-employed mothers and children in the lowest income households, lower coverage was observed compared to children of mothers in employment and children in the highest income households (-8% and -7% in cohort 2020, respectively). Nearly identical trends were observed for DTaP-IPV vaccination. Conclusion: Our study reveals a significant decline in childhood vaccination coverage in the Netherlands, with increasing disparities between sociodemographic groups. This is crucial for prioritising vaccination efforts to protect public health equitably. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Dutch Ministry of Health, Welfare, and Sport. The funder had no role in the design, data collection, data analysis, and reporting of this study. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Centre for Clinical Expertise at the Institute for Public Health and the Environment (RIVM) assessed the research proposal (EPI-644). They verified whether the work complies with the specific conditions as stated in the law for medical research involving human subjects (WMO). They are of the opinion that the research does not fulfil one or both of these conditions and therefore conclude it is exempted for further approval by the ethical research committee. The individual level data (from national registries) was de-identified prior to its use in our study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data is available within CBS Microdata and can be made available under strict conditions.

BACKGROUND:During the COVID-19 pandemic, the National Institute for Public Health and the Environment in the Netherlands developed a pipeline of scripts to automate and streamline the production of epidemiological situation reports (epi‑sitrep). The pipeline was developed for the Automation of Data Import, Summarization, and Communication (hereafter called the A-DISC pipeline). OBJECTIVE:This paper describes the A-DISC pipeline and provides a customizable scripts template that may be useful for other countries wanting to automate their infectious disease surveillance processes. METHODS:The A-DISC pipeline was developed using the open-source statistical software R. It is organized in four modules: Prepare, Process data, Produce report, and Communicate. The Prepare scripts set the working environment (e.g., load packages). The (data-specific) Process data scripts import, validate, verify, transform, save, analyze, and summarize data as tables and figures and store these data summaries. The Produce report scripts gather summaries from multiple data sources and integrate them into a RMarkdown document - the epi‑sitrep. The Communicate scripts send e-mails to stakeholders with the epi‑sitrep. RESULTS:As of March 2023, up to ten data sources were automatically summarized into tables and figures by A-DISC. These data summaries were featured in routine extensive COVID-19 epi‑sitreps, shared as open data, plotted on RIVM's website, sent to stakeholders and submitted to European Centre for Disease Prevention and Control via the European Surveillance System -TESSy [38]. DISCUSSION:In the face of an unprecedented high number of cases being reported during the COVID-19 pandemic, the A-DISC pipeline was essential to produce frequent and comprehensive epi‑sitreps. A-DISC's modular and intuitive structure allowed for the integration of data sources of varying complexities, encouraged collaboration among people with various R-scripting capabilities, and improved data lineage. The A-DISC pipeline remains under active development and is currently being used in modified form for the automatization and professionalization of various other disease surveillance processes at the RIVM, with high acceptance from the participant epidemiologists. CONCLUSION:The A-DISC pipeline is an open-source, robust, and customizable tool for automating epi‑sitreps based on multiple data sources.

Objectives: Studies have shown temporal changes in post-acute sequelae of COVID-19 (PASC) prevalence for early SARS-CoV-2 variants, although often lacking controls. This prospective study assesses the prevalence of symptoms in Delta- and Omicron-infected cases up to 12 months compared with population controls. Methods: Adult participants filled out surveys every 3 months (T0-T12) between July 2021 and August 2023. Cases were recruited with a positive SARS-CoV-2 test during the Delta or Omicron domination. Population controls were randomly invited from the Dutch Personal Records Database. Participants indicated the presence of 13 PASC-associated symptoms, and severity scores of fatigue, cognitive impairment, dyspnea, and pain. PASC prevalence was defined as the excess prevalence of havingat least one PASC-associated symptom in cases compared with population controls. Results: PASC prevalence was 34.3% at T3 and decreased to 21.7% at T12 for Delta and decreased from 18.7% at T3 to 16.7% at T12 for Omicron. At T12, the difference between Delta and Omicron was not significant. Delta cases generally had higher excess symptom scores for fatigue, dyspnea, and cognitive impairment than Omicron. Conclusions: In the first 9 months after infection, PASC prevalence was higher for Delta than Omicron, but the difference reduced over time and approximated after 12 months.

BACKGROUND:SARS-CoV-2 can be effectively transmitted between individuals located in close proximity to each other for extended durations. Aircraft provide such conditions. Although high attack rates during flights were reported, little was known about the risk levels of aerosol transmission of SARS-CoV-2 in aircraft cabins. OBJECTIVES:The major objective was to estimate the risk of contracting COVID-19 from transmission of aerosol particles in aircraft cabins. METHODS:In two single-aisle and one twin-aisle aircraft, dispersion of generated aerosol particles over a seven-row economy class cabin section was measured under cruise and taxi conditions and simulated with a computational fluid dynamic model under cruise conditions. Using the aerosol particle dispersion data, a quantitative microbial risk assessment was conducted for scenarios with an asymptomatic infectious person expelling aerosol particles by breathing and speaking. Effects of flight conditions were evaluated using generalized additive mixed models. RESULTS:Aerosol particle concentration decreased with increasing distance from the infectious person, and this decrease varied with direction. On a typical flight with an average shedder, estimated mean risk of contracting COVID-19 ranged from 1.3×10-3 to 9.0×10-2. Risk increased to 7.7×10-2 with a super shedder (<3% of cases) on a long flight. Risks increased with increasing flight duration: 2-23 cruise flights of typical duration and 2-10 flights of longer duration resulted in at least 1 case of COVID-19 due to onboard aerosol transmission by one average shedder, and in the case of one super shedder, at least 1 case in 1-3 flights of typical duration cruise and 1 flight of longer duration. DISCUSSION:Our findings indicate that the risk of contracting COVID-19 by aerosol transmission in an aircraft cabin is low, but it will not be zero. Testing before boarding may help reduce the chance of a (super)shedder boarding an aircraft and mask use further reduces aerosol transmission in the aircraft cabin. https://doi.org/10.1289/EHP11495.

Background: There is debate as to whether a coronavirus infection (SARS-CoV-2) affects older adults physical activity, sleeping problems, weight, feelings of social isolation, and quality of life (QoL). We investigated differences in these outcomes between older adults with and without coronavirus infection over 180 days following infection. Methods: We included 6789 older adults (65+) from the Lifelines COVID-19 cohort study who provided data between April 2020 and June 2021. Older adults (65+) with and without coronavirus infection were matched on sex, age, education, living situation, body mass index, smoking status, vulnerable health, time of infection, and precoronavirus health outcome. Weighted linear mixed models, adjusted for strictness of governmental policy measures, were used to compare health outcomes after infection between groups. Results: In total, 309 participants were tested positive for coronavirus. Eight days after infection, older adults with a coronavirus infection engaged in less physical activity, had more sleeping problems, weighed less, felt more socially isolated, and had a lower QoL than those without an infection. Differences in weight, feelings of social isolation, and QoL were absent after 90 days. However, differences in physical activity were still present at 90 days following infection and sleeping problems were present at 180 days. Conclusion: Our findings found negative associations of coronavirus infection with all the examined outcomes, which for physical activity persisted for 90 days and sleeping problems for 180 days. Magnitudes of estimated effects on physical activity and sleeping problems remain uncertain.

Abstract Background The successful promotion of health-enhancing physical activity (HEPA) requires reliable and valid prevalence data of physical activity (PA) to enable the design, implementation and evaluation of effective and cost-effective policies. As part of the development of a new integrated monitoring framework in Europe, the reliability and validity of the Eurobarometer, European Health Interview Survey (EHIS), International Physical Activity Questionnaire (IPAQ) and Global Physical Activity Questionnaire (GPAQ) were studied in the ongoing European Union Physical Activity and Sport Monitoring System project (EUPASMOS) among 18 European Union member states. Methods Physical activity (PA) and sedentary behavior (SB) were assessed among 80-100 adults per member state using the four questionnaires and the UKK RM42 accelerometer. Participants completed the questionnaires in random order and wore the accelerometer seven consecutive days on their right hip (during the day) and on their non-dominant wrist (overnight). Time spent in moderate-to-vigorous intensity physical activity (MVPA), sedentary behavior and adherence to the WHO PA guidelines were calculated based on the 5 methods. The reproducibility and validity of the four questionnaires were tested by using the Spearman's correlation coefficient (ρ) or Cohen's kappa coefficient (κ), dependent of the outcome measure. Results Preliminary results from the Netherlands (N = 91) showed that the correlations for reproducibility of all four questionnaires varied between 0.51 and 0.63 for MVPA, between 0.30 and 0.60 for the WHO PA guidelines and between 0.65 and 0.82 for SB. All correlations were statically significant (p > 0.05). Significant correlations for validity of the questionnaires were found for MVPA (ρ = 0.22-0.43) and the WHO PA guidelines (ρ = 0.19-0.25). The only exception was the association between the EHIS questionnaire and the WHO PA guidelines. For SB, only GPAQ and the EHIS questionnaire showed significant associations (ρ = 0.31-0.32). Conclusions First analyses of the Dutch data within the EUPASMOS project showed that the four commonly used questionnaires in Europe are fairly to strongly reliable methods depending on the outcome measure. The four questionnaires are fairly valid methods, except the Eurobarometer and IPAQ when examining SB. It is of interest to examine the quality of these questionnaires in all 18 member states for national and European policy makers.

Cognitive decline is part of the normal aging process. However, some people experience a more rapid decline than others due to environmental and genetic factors. Numerous single nucleotide polymorphisms (SNPs) have been linked to cognitive function, but only a few to cognitive decline. To understand whether cognitive function and cognitive decline are driven by the same mechanisms, we investigated whether 433 SNPs previously linked to cognitive function and 2 SNPs previously linked to cognitive decline are associated with both general cognitive functioning at baseline and general cognitive decline up to 20-years follow-up in the Doetinchem Cohort Study (DCS). The DCS is a longitudinal population-based study that enrolled men and women aged 20–59 years between 1987–1991, with follow-up examinations every 5 years. We used data of rounds 2–6 (1993–2017, n = 2559). General cognitive function was assessed using four cognition tests measuring memory, speed, fluency and flexibility. With these test scores, standardized residuals (adjusted for sex, age and examination round) were calculated for each cognition test at each round and subsequently combined into one general cognitive function measure using principal component analyses. None of the 435 previously identified variants were associated with baseline general cognitive function in the DCS. But rs429358-C, a coding apolipoprotein E (APOE) SNP and one of the variants previously associated with cognitive decline, was associated with general cognitive decline in our study as well ( p -value = 1 × 10 −5 , Beta = −0.013). These findings suggest that decline of general cognitive function is influenced by other mechanisms than those that are involved in the regulation of general cognitive function.

Background: Although drinking water in the Netherlands is generally accepted as safe, public concern about health risks of long-term intake still exist. Objective: The aim was to explore associations between drinking water quality for nitrate, water hardness, cal-cium and magnesium and causes-of-death as related to cardiovascular diseases amongst which coronary heart disease and colorectal cancer. Methods: We used national administrative databases on cause-specific mortality, personal characteristics, resi-dential history, social economic indicators, air quality and drinking water quality for parameters specified by the EU Drinking Water Directive. We put together a cohort of 6,998,623 persons who were at least 30 years old on January 1, 2008 and lived for at least five years on the same address. The average drinking water concentration over 2000-2010 at the production stations were used as exposure indicators. We applied age stratified Cox proportional hazards models. Results: Magnesium was associated with a reduced risk for mortality due to coronary heart diseases: HR of 0.95 (95% CI: 0.90, 0.99) per 10 mg/L increase. For mortality due to cardiovascular diseases, a 100 mg/L increase in calcium was associated with a HR of 1.08 (95% CI: 1.03, 1.13) and an increase of 2.5 mmol/L of water hardness with a HR of 1.06 (95% CI: 1.01, 1.10). The results show an elevated risk for coronary heart disease mortality at calcium concentrations below 30 mg/L, but over the whole exposure range no exposure response relation was observed. For other combinations of drinking water quality parameters and cause-specific mortality studied, no statistical significant associations were identified. Conclusion: We identified in this explorative study a protective effect of magnesium for the risk of mortality to coronary heart disease. Also we found an increased risk of mortality due to cardiovascular disease associated with the concentration of calcium and the water hardness in drinking water.

ObjectivesWe aimed to identify populations at a high risk for SARS-CoV-2 infection but who are less likely to present for testing, by determining which sociodemographic and household factors are associated with a lower propensity to be tested and, if tested, with a higher risk of a positive test result.Design and settingInternet-based participatory surveillance data from the general population of the Netherlands.ParticipantsWeekly survey data collected over a 5-month period (17 November 2020 to 18 April 2021) from a total of 12 026 participants who had contributed at least 2 weekly surveys was analysed.MethodsMultivariable analyses using generalised estimating equations for binomial outcomes were conducted to estimate the adjusted ORs of testing and of test positivity associated with participant and household characteristics.ResultsMale sex (adjusted OR for testing (ORt): 0.92; adjusted OR for positivity (ORp): 1.30, age groups<20 (ORt: 0.89; ORp: 1.27), 50–64 years (ORt: 0.94; ORp: 1.06) and 65+ years (ORt: 0.78; ORp: 1.24), diabetics (ORt: 0.97; ORp: 1.06) and sales/administrative employees (ORt: 0.93; ORp: 1.90) were distinguished as lower test propensity/higher test positivity factors.ConclusionsThe factors identified using this approach can help identify potential target groups for improving communication and encouraging testing among those with symptoms, and thus increase the effectiveness of testing, which is essential for the response to the COVID-19 pandemic and for public health strategies in the longer term.

Background Voluntary testing for SARS-CoV-2 infection is an integral component of an effective response to the COVID-19 pandemic. It is essential to identify populations at a high risk for infection but who are less likely to present for testing. Here, we use internet-based participatory surveillance data from the Netherlands to identify sociodemographic and household factors that are associated with a lower propensity to be tested and, if tested, with a higher risk of a positive test result. Methods Multivariable analyses using generalised estimating equations for binomial outcomes were conducted to estimate the adjusted odds ratios of testing and of positivity associated with participant and household characteristics. Results Based on five months (17 November 2020 to 18 April 2021) of weekly surveys obtained from 12,026 participants, males (adjusted odds ratio for testing (OR t ): 0.92; adjusted odds ratio for positivity (OR p ): 1.30, age-groups <20 (OR t : 0.89; OR p : 1.27) 50-64 years (OR t : 0.94; OR p : 1.06) and 65+ years (OR t : 0.78; OR p : 1.24), diabetics (OR t : 0.97; OR p : 1.06), and sales/administrative employees (OR t : 0.93; OR p : 1.90) were distinguished as lower propensity/higher positivity factors. Conclusions The factors identified using this approach can help identify potential target groups for improving communication and encouraging testing among those with symptoms and thus increase the effectiveness of testing, which is essential for the response to the COVID-19 pandemic and for public health strategies in the longer term .

Abstract It is unclear to what extent self‐employed choose to become self‐employed. This study aimed to compare the health care expenditures—as a proxy for health—of self‐employed individuals in the year before they started their business, to that of employees. Differences by sex, age, and industry were studied. In total, 5,741,457 individuals aged 25–65 years who were listed in the tax data between 2010 and 2015 with data on their health insurance claims were included. Self‐employed and employees were stratified according to sex, age, household position, personal income, region, and industry for each of the years covered. Weighted linear regression was used to compare health care expenditures in the preceding (year x–1) between self‐employed and employees (in year x). Compared with employees, expenditures for hospital care, pharmaceutical care and mental health care were lower among self‐employed in the year before they started their business. Differences were most pronounced for men, individuals ≥40 years and those working in the industry and energy sector, construction, financial institutions, and government and care. We conclude that healthy individuals are overrepresented among the self‐employed, which is more pronounced in certain subgroups. Further qualitative research is needed to investigate the reasons why these subgroups are more likely to choose to become self‐employed.

The Healthy Aging Index (HAI), an index of physiological aging, has been demonstrated to predicts mortality, morbidity and disability. We studied the longitudinal development of the HAI to identify aging trajectories and evaluated the role of baseline sociodemographic characteristics and lifestyle factors of the trajectories. Four measurements with intervals of 5 years were included from the Doetinchem Cohort Study. The HAI reflects levels of systolic blood pressure, non-fasting plasma glucose levels, global cognitive functioning, plasma creatinine levels and lung functioning. The HAI score ranges from 0 to 10: higher scores indicate a better health profile. Latent class mixture modelling was used to model within-person change and to identify aging trajectories. Area under the curve was calculated per trajectory to estimate total healthy years. In total, 2324 women and 2013 men were included. One HAI trajectory was identified for women, and two trajectories for men, labelled 'gradual' aging (76%) and 'early' aging (24%). Men who were medium/high educated, below 36 years at baseline, complied with guidelines on physical activity and were not obese in any round were associated with increased odds to 'gradual' aging of 1.46 (CI: 1.18-1.81), 1.93 (CI: 1.42-2.62), 1.26 (1.02-1.57) and 1.76 (1.32-2.35), respectively. Between 30 and 70 years of age, men in the 'early' aging trajectory had the least healthy years (29.6 years), followed by women (30.1 years), and 'gradual' aging men (34.7 years). This study emphasizes that 'physiological aging' is not only an issue of older ages. Between 30 and 70 years of age, 'early' aging men and women had approximately five healthy years less compared to 'gradual' aging men. Lifestyle factors (e.g. nutrition and physical activity) seem to play an important role in optimal aging.

Background: Infections with parvovirus B19 (B19V) have been associated with a wide range of disease manifestations of which erythema infectiosum (fifth disease) in children is most common. Clinical signs following infection of children with B19V can be similar to measles and rubella. Laboratory detection of B19V infections is based on detection of B19V-specific IgM antibodies by enzyme immunoassay (IgM-EIA) and/or B19V DNA by quantitative PCR (qPCR) on blood samples. The need for invasive sampling can be a barrier for public health diagnostics. Objectives: To evaluate the use of a dual target B19V-qPCR directed against the NS1 and VP2 of B19V on oral fluid samples as a non-invasive alternative for laboratory diagnosis of B19V infections in children below 12 years of age with exanthema. Study design: Oral fluid and serum samples were collected from 116 children with exanthema. All serum samples were tested by IgM-EIA/IgG-EIA, while all oral fluid and 56 serum samples were tested by B19V-qPCR. Results: B19V-specific IgM antibodies were detected in 25 of 116 children in the study. B19V DNA was detected in oral fluid in 17 of the 25 children who were IgM positive, as well as two children who were IgM-equivocal or negative. The child with the equivocal IgM had a high quantity of B19V DNA in oral fluid (7 log IU/ml), compatible with an acute B19V infection. The IgM-negative child was IgG-positive and 4 log IU/ml B19V DNA was detected in the oral fluid sample, suggesting an acute infection and a falsely negative IgM. Sample size calculations indicated that oral fluid samples for qPCR should be collected from 2 to 3 children during outbreaks of exanthema to achieve similar sensitivity as IgM-EIA for one child (>= 0.9) to confirm or exclude B19V. Conclusions: Results indicate that oral fluid samples are a suitable public health alternative for detection of B19V infections, potentially lowering the barriers for sampling.

OPS 26: Radiation, EMF, cancer and mortality, Room 114, Floor 1, August 26, 2019, 4:30 PM - 5:45 PM Background/Aim: Some people attribute non-specific physical symptoms (NSPS) such as headache and fatigue to exposure to radiofrequency electromagnetic fields (RF-EMF). Most studies into exposure-response associations in electrosensitivity were short-term laboratory studies, only suitable to detect symptoms elicited by acute exposure. We will present the results from two studies with an ambulatory design using body worn exposimeters and electronic diaries that aimed to analyse exposure-response relationships in self-declared electrosensitive persons both at a group and individual level. Methods: In study 1, seven participants registered NSPS and perceived RF-EMF exposure in an electronic diary daily at three set times for a period of three weeks. During the same period personal exposure was monitored using exposimeters. A second study including 57 participants used a similar design but the study period was five days and diaries were completed at quasi-random times with 2-3 hour intervals. Associations between EMF exposure and NSPS were analysed using ARIMA and (linear) mixed models. Results: In study 1, we found statistically significant associations between perceived and actual exposure to WiFi and base stations for mobile telecommunications and NSPS scores in four participants. In two persons a higher EMF exposure was statistically significantly associated with higher symptom scores, and in two other persons it was associated with lower scores. Strengths of the associations were in the order of a 0.4 to 0.9 increase or decrease in symptom scores (on a five-point scale) for an increase of 2 standard deviations in EMF exposure. In study 2, at group level, there was no statistically significant association between EMF exposure and NSPS. Analyses at an individual level are ongoing and will be presented at the conference. Conclusions: RF-EMF exposure was associated either positively or negatively with NSPS in some but not all of the selected self-declared electrohypersensitive persons.